Within the last 10-20 years, hand-held power-operated vegetation trimmers having a whirling string or monofilament line, have become very popular as devices for cutting weeds, edging lawns, mowing in areas inaccessible to mowers, and for similar tasks. Although many companies market such devices under many trademarks, probably the best known are the ones sold under the trademark "Weedeater". It is understood that, generically, such devices are referred to as "string trimmers" or "line trimmers", regardless of the fact that they are not a kind of device used for trimming a string or line, but a kind of device which uses a string or line to trim something else, namely vegetation. Thus, the terms "string trimmer", "line trimmer" and "rotating flexible line-type vegetation trimmer" are used synonymously herein.
There are some differences among the conventional trimmers; some are electric motor-powered, other are gasoline engine-powered, it is conceivable some are hydraulic or pneumatic motor powered. Some have straight handle shafts, others have curved handle shafts. The present invention is meant to be used with any of these regardless of which type of motor they have, and regardless of whether they have straight or curved handle shafts.
Most conventional trimmers are meant to be used while the line is whipping around in a generally horizontal plane about a generally vertical axis. Other orientations are possible, but, when used in other orientations (e.g., with the line whipping around in a vertical plane), the shield normally provided on the device for preventing bits of vegetation, line, dirt and gravel from flying up into user's and bystander's face. Despite manufacturer's instructions to the contrary, some people use the devices on edge anyway, and, in fact, some prior inventors have devised wheeled supports for supporting line trimmers in an on-edge orientation.
In general, conventional line trimmers are designed in the form of a downwardly facing rotary head, covered by a radially projecting arcuate shield having a down-turned flange at its radially outer end, the head and shield being mounted to the lower end of a substantially rigid, generally tubular shaft having one handle at its upper end, and often another, radially projecting handle adjustably located at an intermediate height.
For trimming jobs of short duration performed by a reasonably athletic youngster, the typical conventional trimmer works very well, but the longer the job, the more "out-of-shape", tired, elderly or not-so-strong the user, the more likely that person will leave the job undone, partly done, or be achy from muscle strain after use of such a conventional device. The main problem is that they have to cantilever so much weight so far from their body, and swing it around in arcs and back and forth, basically without any support of the head from the ground. (In fact, bumping the hub at the bottom-center of the head against the ground is used in some designs of trimmers as a means for initiating a feed-out of an increment of the line coiled on a spool in the head.)
A main purpose of the device of the present invention is to provide a wheeled support for a conventional line trimmer, which can be mounted to conventional line trimmers of widely varying designs, yet allow them to be used in the manufacturer's intended orientation (in which the line whirls from one end in a generally horizontal plane about a generally vertical axis, while protected by a covering shield).